As synthesis reaction systems which synthesize hydrocarbon compounds by a Fischer-Tropsch synthesis reaction (hereinafter referred to as “FT synthesis reaction”) by using a synthesis gas mainly composed of carbon monoxide (CO) gas and hydrogen gas (H2) as a raw material gas, for example, like the PATENT DOCUMENT 1, there is a bubble column type slurry bed FT reaction system which carries out the FT synthesis reaction by introducing the synthesis gas into a slurry in which solid catalyst particles are suspended in liquid hydrocarbons. Further, a hydrocarbon compound synthesized by the FT synthesis reaction is mainly utilized as a raw material for liquid fuel products such as naphtha (raw gasoline), kerosene, and gas oil.
Further, as this bubble column type slurry bed FT reaction system, for example, there is a so-called external circulation type FT reaction system including a reactor main body which accommodates a slurry, and a gas supply section which introduces synthesis gas into the bottom of the reactor main body, and an external circulation section which makes the slurry including a hydrocarbon compound synthesized within the reactor main body flow out of the reactor main body, and makes the slurry flow into the reactor main body again via a separator which separates the hydrocarbon compound from the slurry.
However, the particle diameter of the catalyst particles included in the slurry may become gradually small due to friction between catalyst particles, the friction with an inner wall of the reactor main body, or the like, and any thermal damage by the FT synthesis reaction, that is, the catalyst particles are powdered gradually. As such, since the powdered catalyst particles (hereinafter referred to as powdered particles) are apparently smaller than normal catalyst particles which are not powdered, the powdered particles may flow into next section (upgrading section) of producing liquid fuel products along with the hydrocarbon compound which are separated while not being trapped in the separator. When the powdered particles flow into the upgrading section of liquid fuel products, there is a probability that deterioration of a catalyst to be used in the step or deterioration of the liquid fuel products may be caused.
[PATENT DOCUMENT 1] Specification of US Patent Application Publication No. 2007-0014703